Photocatalytic-Fenton synergistic reaction of CuFeO2/Fe2O3 heterostructure for tetracycline hydrochloride degradation

The heterogeneous photocatalytic-Fenton synergistic reaction is regarded as a promising technique for organic pollutants degradation due to its efficient utilization of solar energy and high H₂O₂ activation activity. Herein, a CuFeO₂/Fe₂O₃ heterostructure with Fe³⁺/Fe²⁺ and Cu²⁺/Cu⁺ double redox couples were fabricated via a hydrothermal process. Compared with the pristine CuFeO₂ and Fe₂O₃, the CuFeO₂/Fe₂O₃ heterostructure displays much-increased photocatalytic-Fenton synergistic reaction activity, with tetracycline hydrochloride (TCH) removal by 97.04 % within 135 min. Meanwhile, the CuFeO₂/Fe₂O₃ heterostructure system exhibits excellent stability and efficiency in degrading TCH across a wide pH range of 2–9. The efficient TCH degradation activity should be mainly ascribed to the characteristics of the built-in redox couples (Fe³⁺/Fe²⁺ and Cu²⁺/Cu⁺) effectively promote the activation of H₂O₂, which is highly benefits the formation of more active species. Additionally, theoretical calculations elucidate the establishment of strong built-in electric field at the heterointerface of CuFeO₂ and Fe₂O₃, encouraging the effective separation and transfer of photoinduced electrons and holes. This, in turn, promotes the in-situ recycling of Cu²⁺ to Cu⁺ and Fe³⁺ to Fe²⁺. This work provides new insights for fabricating novel heterostructure for the effective photocatalytic-Fenton remediation of wastewater containing antibiotic contaminants.